The Gaoyou-Baoying M

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4.9 earthquake is the most significant earthquake on land in Jiangsu Province in the past 28 years.Its epicenter was located in the central part of Jiangsu Province.The earthquake precursors were abundant and its spatial and temporal evolution characteristics were typical.In the two years before the earthquake

stress-compression zone developed in the epicenter and tensile zone formed in the surrounding areas

showing up as quasi-synchronous changes of water level

ground resistivity and deformation.The convergence of small earthquake band activities occurred intensively in one year before the earthquake.The instability of rock fissure changes appeared in one month before the earthquake

which was charact

erized by short-term rapid changes of surrounding water temperature and hydrochemistry.The spatial and temporal evolution characteristics of anomalies before the Gaoyou-Baoying M

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4.9 earthquake reflect the deformation and fissure changes of surrounding rocks during seismogenic process

which has a good referential value in moderate and strong earthquake prediction.